Citations

Abstract Background Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10−8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. Methods We conducted a GWAS in European descent CRC cases and control subjects using a discovery–replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10−8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. Results The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10−8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. Conclusions This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screening.

SummaryObjectiveThe multicenter National Infantile Spasms Consortium prospective cohort was used to compare outcomes and phenotypic features of patients with infantile spasms with and without hypsarrhythmia.MethodsPatients aged 2 months to 2 years were enrolled prospectively with new‐onset infantile spasms. Treatment choice and categorization of hypsarrhythmia were determined clinically at each site. Response to therapy was defined as resolution of clinical spasms (and hypsarrhythmia if present) without relapse 3 months after initiation.ResultsEighty‐two percent of patients had hypsarrhythmia, but this was not associated with gender, mean age, preexisting developmental delay or epilepsy, etiology, or response to first‐line therapy. Infants with hypsarrhythmia were more likely to receive standard treatment (adrenocorticotropic hormone, prednisolone, or vigabatrin [odds ratio (OR) 2.6, 95% confidence interval (CI) 1.4–4.7] and preexisting epilepsy reduced the likelihood of standard treatment (OR3.2, 95%CI1.9–5.4). Hypsarrhythmia was not a determinant of response to treatment. A logistic regression model demonstrated that later age of onset (OR1.09 per month, 95%CI1.03–1.15) and absence of preexisting epilepsy (OR1.7, 95%CI1.06–2.81) had a small impact on the likelihood of responding to the first‐line treatment. However, receiving standard first‐line treatment increased the likelihood of responding dramatically: vigabatrin (OR5.2 ,95%CI2–13.7), prednisolone (OR8, 95%CI3.1–20.6), and adrenocorticotropic hormone (ACTH;OR10.2, 95%CI4.1–25.8) .SignificanceFirst‐line treatment with standard therapy was by far the most important variable in determining likelihood of response to treatment of infantile spasms with or without hypsarrhythmia.

Abstract Background GNE myopathy is a rare genetic disease characterized by progressive muscle atrophy and weakness. It is caused by biallelic mutations in the GNE gene that encodes for the bifunctional enzyme, uridine diphosphate ( UDP )‐N‐acetylglucosamine (Glc NA c) 2‐epimerase/N‐acetylmannosamine (Man NA c) kinase. Typical characteristics of GNE myopathy include progressive myopathy, first involving anterior tibialis muscle and sparing the quadriceps, and rimmed vacuoles on muscle biopsy. Identifying biallelic mutations by sequencing of the GNE gene confirms the diagnosis of GNE myopathy. In a subset of patients, diagnostic confirmation is challenged by the identification of mutations in only one allele, suggesting mutations in deep intronic regions or regulatory regions. Methods We performed targeted sequencing and copy number variant ( CNV ) analysis of GNE in two siblings who clinically presented with GNE myopathy. Further molecular and biochemical studies were done to characterize the effect of a previously uncharacterized GNE mutation. Results We report two siblings of Indian descent with characteristic features of GNE myopathy, including progressive skeletal muscle weakness initially involving the anterior tibialis, and rimmed vacuoles on muscle biopsy, in which a heterozygous mutation, p.Val727Met, was identified in both affected siblings, but no other deleterious variants in either coding region or exon–intron boundaries of the gene. Subsequent insertion/deletion analysis identified a novel 11.3‐kb deletion (Chr9 [ GRC h37]: g.36257583_36268910del) encompassing the GNE promoter region, with breakpoints residing in Alu repeats. Gene expression analysis revealed reduced GNE mRNA and protein levels, confirming decreased expression of the deleted allele harboring the deletion. Conclusions We have identified GNE as one of the genes susceptible to Alu ‐mediated recombination. Our findings suggest that the deletion may encompass the promoter or another region necessary for GNE expression. In patients with typical manifestations of GNE myopathy and a single GNE variant identified, copy number variant ( CNV ) analysis may be useful in arriving at the diagnosis.

572 Background: Renal medullary carcinoma (RMC) is an aggressive malignancy affecting predominantly young African Americans with sickle cell trait (SCT) or disease (SCD), while a pathologically similar collecting duct carcinoma (CDC) affects patients without sickle cell trait. Clinical responses to chemotherapy and IL-2 in RMC/CDC are poor and novel therapies are needed. Methods: 9 patients with RMC (ages 13-58 y. o., all male) and 15 patients (ages 26-74 y. o., M:F = 13:2) with collecting duct carcinoma (CDC) were studied. Expression of PD-L1 was evaluated with 2 monoclonal antibodies (SP142 and SP263) and tumor infiltrating lymphocytes (TIL) were evaluated for PD1 expression (MRQ-22 antibody) using immunohistochemistry (IHC). Additional studies included ALK protein expression (D5F3 antibody), gene translocation (break apart FISH), next generation sequencing (NGS), and microsatellite instability (MSI). Results: Cancer cell PD-L1 expression above the threshold ( ≥ 2+, ≥ 5%) was seen in 7/9 RMC and 5/13 CDC cases. Concordance between 2 PD-L1 antibodies was 94.4%. PD-1+ TIL were absent in 6/18 cases and variably present in 12/18 cases (from 1 to > 15 TIL/40x power field). No MSI was detected in any of the cases tested (0/6). No case expressed ALK protein, but one case of CDC showed ALK gene re-arrangement. Mutations were identified in SMARCB1, FH, TP53 (3x), ATM, BRCA2, CHEK2 (2x), NF2 (3x), SETD2, and CDKN2A. No mutations in VHL or KDR were detected. One patient with RMC (and SCT) achieved complete clinical remission after treatment with bevacizumab plus paclitaxel. Conclusions: RMC and CDC strongly express PD-L1 in the majority of cases (12/22), suggesting that these patients may benefit from targeting the PD-L1/PD1 interaction. The absence of MSI in these cancers indicates a different mechanism of PD-L1 upregulation from colorectal carcinomas. Consistent with our previous study that showed frequent activation of (pseudo)hypoxia-induced pathways in RMCs (Human Pathology 2011;42:1979), we describe a case of RMC successfully treated with anti-VEGF therapy.

Purpose of review Norovirus infection is an emerging chronic infection in immunocompromised hosts. The aim of this review is to discuss the pathophysiology of Norovirus infection and explore mechanistic models for chronic infection/shedder state, especially in patients with immune deficiency diseases. Recent findings Chronic Norovirus infection is increasingly associated with enteropathy associated with both primary and secondary immune deficiency diseases. There is an ongoing debate in the immune deficiency community whether it is truly a causative agent for the enteropathy or it is an innocent bystander. We describe the historic aspects of Norovirus infection, its immunology and viral structure and the basis for preventive and vaccination strategies. We also postulate in this review a disease model in immune deficiency subjects which creates a milieu for it to become a chronic and explore newer frontiers for disease modification and prevention. Summary Norovirus is the most common cause of acute gastroenteritis in general population but the factors that lead to its persistence in patients with immune deficiency need further holistic studies. This should include host assessment, microbiome signatures, and viral pathogenic factors assessment.

Summary Objective Infantile spasms ( IS ) represent a severe epileptic encephalopathy presenting in the first 2 years of life. Recommended first‐line therapies (hormonal therapy or vigabatrin) often fail. We evaluated response to second treatment for IS in children in whom the initial therapy failed to produce both clinical remission and electrographic resolution of hypsarhythmia and whether time to treatment was related to outcome. Methods The National Infantile Spasms Consortium established a multicenter, prospective database enrolling infants with new diagnosis of IS. Children were considered nonresponders to first treatment if there was no clinical remission or persistence of hypsarhythmia. Treatment was evaluated as hormonal therapy (adrenocorticotropic hormone [ ACTH ] or oral corticosteroids), vigabatrin, or “other.” Standard treatments (hormonal and vigabatrin) were compared to all other nonstandard treatments. We compared response rates using chi‐square tests and multivariable logistic regression models. Results One hundred eighteen infants were included from 19 centers. Overall response rate to a second treatment was 37% (n = 44). Children who received standard medications with differing mechanisms for first and second treatment had higher response rates than other sequences (27/49 [55%] vs. 17/69 [25%], p < 0.001). Children receiving first treatment within 4 weeks of IS onset had a higher response rate to second treatment than those initially treated later (36/82 [44%] vs. 8/34 [24%], p = 0.040). Significance Greater than one third of children with IS will respond to a second medication. Choosing a standard medication ( ACTH , oral corticosteroids, or vigabatrin) that has a different mechanism of action appears to be more effective. Rapid initial treatment increases the likelihood of response to the second treatment.

The term disappearing HDL syndrome refers to development of severe high density lipoprotein cholesterol (HDL-C) deficiency in noncritically ill patients with previously normal HDL-C and triglyceride levels. Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of the immune system due to an inability to regulate lymphocyte homeostasis resulting in lymphadenopathy and hepatosplenomegaly. We describe a 17-year-old boy who was evaluated in the lipid clinic for history of undetectable or low HDL-C and low density lipoprotein cholesterol (LDL-C) levels. Past medical history was significant for ALPS IA diagnosed at 10 years of age when he presented with bilateral cervical adenopathy. He was known to have a missense mutation in one allele of the FAS protein extracellular domain consistent with ALPS type 1A. HDL-C and LDL-C levels had been undetectable on multiple occasions, though lipids had not been measured prior to the diagnosis of ALPS. He had been receiving sirolimus for immunosuppression. The HDL-C and LDL-C levels correlated with disease activity and improved to normal levels during times when the activity of ALPS was controlled. This case highlights the importance of considering ALPS as a cause of low HDL-C and LDL-C levels in a child with evidence of lymphoproliferation.